Wireless telegraphy.



110. 737,072. PATENTED AUG. 25,1903.

I c. G. BURKE. WI ELESS TELEGRAPHY. APPLICATION FILED SEPT. 21, 1901.

K0 MODEL.

W GO 000 0 O O O 0 \O0 O0 0 v M THE NORRIS Fergus co, PHOTO LIITHDW WASHINGTON, n. c.

WITNESSES: I

UNITED STATES- Ilatehted August 25, I903.

PATENT OF ICE.

CHARLES e. BURKE, OF NEW Y RK, N. 'Y.

WIRELESSII'ELEGRAPHY.

SPECIFICATION forming part of Letters Patent No. 737,072, dated August 25, 1903 :Application filed September 21,1901. Serial No. 76,059. (no model.)

To all whom it may concern:

city of New York, in the borough of Brooklyn and State of New York, have; invented certain new and useful Improvements in .Wireless Telegraphy, of which the. following is a i i apparatus of a transmitting and receiving full, clear, and exact description.

In wireless telegraphy it is usual to employ the Morse code for the transmission and recording of messages. The signals in this code are composed of dots and dashes, and these dots and dashes are produced in wireless telegraphy by the impulses sent into space from a sending-station acting through a coherer in the receiving-station, which controls a local battery and local recorder. Inasmuch as the impulses sent into space in wireless telegraphy are necessarily uniformin their duration and that two or more ofsuch impulses are needed to complete each dash and that the circuit continuity of the cohererv has to be interrupted at the end of each impulse it has not heretofore been possiblein wireless telegraphy to produce dashes with the same facility and accuracy as it has been to produce dots. The tapping of the coherer after each impulse mutilates the dashes to such an extent that the deciphering ot the record hecomes more or less guesswork even to skilled operators.

The. purposeof this invention is to enable Morse dashes to be produced in wireless telegraphy as readily and as accurately as Morse dots, and thereby to insure as perfect signals as those made over an ordinary land-line.

In carrying out my improvement I preferably employ what is known as the Cont-i nental-Morse Code, the same which is now in use on all submarine cables and on European land-lines. In recording signals I cause theimpulses to interrupt the continuity of an inked line normally being made by the recorder. Each interruption is of the same length, and that portion of the line traced between the interruptions is either a dot or a dash, depending on the interval between the interruptions. An interval greater than that required to record a dash indicates the Space between letters and is recorded as a long line. The adaptability of this method of transmission to wireless telegraphy, where the current impulses are necessarily of the same duration, is atonce apparent.

My, invention will be described with reference to the 'accompanying drawings, in which Figure l is a diagram of the circuits and station equipped according to my invention. Fig. 2 illustrates sections of the sendingand receiving tapes with characters indicated thereon.

Referring "to the d'rawingsby letter, A- representsa transmitting-station and B a receiving-station for wireless telegraphy. At the station A is located the usual Ruhmkorff coil a or other source of. high-tension electricity. This coil has the usual appliances for producing the oscillations, which appliances may be of any of the well-known forms employed in wireless telegraphy. In the primary circuit 1 of the coil or are the usual'battery a and the circuit-controller a the lat: ter, asillustrated, being operated to close the circuit by an electromagnet b in a circuit 2,

containingbattery b and circuit-controller b The latter devicehas a stylus b adapted to drag upon'the surface of a perforated tape t, which is supported by a Wheel t. When a perforation. in the tape is presented to the stylus, the stylus drops into it and closes the T ted with .its tapping and other. appliances.

The coherer controls the local circuit '3', including battery 0 and electromagnet o The latter acts as a relay to close the recordingcircuit 4, which coutains battery 01 and the recorder-magnet e.

p is a receiving-tape on which the signals are recorded. This tape passes over a wheel 19', supported by the armature-lever e of magnet e. The tape is normally held against the ICO point of a pen or siphon s, so that while the magnet e is denergized a continuous line will be traced on the tape.

The perforations of the sending-tape tare all of the same size; but they are spaced apart variously to indicate dots, dashes, and spaces between letters and words, the shortest space being a dot, the next longer being a dash, the next longer a space between letters, and the longest (when used) being a space between words. Whenever a space between perforations is presented to the stylus b the pen sis against the tape p, as will now appear from the description of the operation.

Under normal conditions when no current is on any of the circuits a continuous line is being traced by the pen upon the tape 19. When a perforation is presented to the stylus b the latter closes the circuit 2 and energizes magnet 17. This closes circuit 1 and allows a current to flow through the primary of the induction-coil a. Immediately thereafter the circuit is broken by the stylus passing out of the perforation, and on the opening of the circuit 1 which follows an impulse of the Hertzian waves is sent out through space from the terminal T. This impulse reaches the receiving-terminal T and aifects the coherer c, which energizes the circuit 3 and its magnet 0 This closes the recorder-circuit 4, causing the armature-lever e to drop the wheel 19, so that the tape is removed from the point of the pen 8. As this impulse is only momentary, the tape 19 is immediately returned to the pen .9, a brief interruption having been made in the traced line to indicate the beginning of a dot. If the next perforation in the tape 6 is the space of a dot from the previous perforation, the circuits described will again be closed immediately, which will cause another interruption in the line on the receiving-tape, the short line between the two spaces defining a dot. If the next perforation in the tapet had been separated from the first by a dash-space, the interruptions of the line on the receiving-tape would have been correspondingly more removed and would have indicated between them a dash. In like manner the larger spaces necessary. for transmission can be sent and received.

It is evident that an ordinary key can be substituted for the circuit-controller 00 and the circuit 2; but owing to the difiiculty of accurately determining the intervals of no current with a hand-key the automatic tape is preferable.

It will thus be seen that by applying to wireless telegraph systems the herein-described means for recording dots and dashes by the mere separation of the impulses the tinuous line and means whereby the line isv interrupted by each impulse, whereby that portion of the line between the interruptions will indicate the signals.

2. In a system of wireless telegraphy, a sending-statiori provided with the usual device, such as a Ruhmkorficoil for creating Hertzian waves, a circuit-controller in the primary circuit of said device, a moving perforated tape whose perforations are of uniform length and whose spaces between the perforations define the signals, and means whereby all perforations will cause uniform changes in the said primary circuit, in combination with a receiving-station provided with the usual imperfect contact-receiver and its local circuit, a moving tape, a linetracer normally tracing a continuous line on said tape and means whereby each response of the coherer will cause an interruption of the traced line. 4

In witness whereof I subscribe my signature in presence of two witnesses.

CHARLES G. BURKE.

\Vitnesses:

FRANK S. OBER, WALDO M. OHAPIN. 

